homework encyclopedia
FIND OUT MORE. Reproduction 101 • Vertebrates 102 119 FOOT SHAPES A LONG JOURNEY 3 The ruby-throated hummingbird migrates thousa ...
120 Nature 1 DOLPHIN Dolphins and whales form a group of mammals called cetaceans. Cetaceans spend their whole lives in water an ...
HIBERNATION Many mammals, such as bats and dormice, survive winter in cool and polar lands by entering a deep sleep called hiber ...
RODENTS With over 2,000 species, rodents make up the largest group of mammals. The smallest rodents weigh just a few grams. The ...
Nature^123 FIND OUT MORE. Feeding 98 • Reproduction 101 • Vertebrates 102 MONOTREMES The small group of egg-laying mammals conta ...
124 Nature Endangered Species All over the world, plant and animal species are now at risk of. EXTINCTION because of changes hum ...
FIND OUT MORE. Farming 66 • Fishing 67 • Forestry 67 • Habitats 82–84 • Human Impact 64–65 • Plants 88–89 WHAT IS THE BEST WAY T ...
...
Body HUMAN BODY SKELETON 130 MUSCLE 132 SKIN 133 CIRCULATION 134 HEART 135 RESPIRATION 136 LUNGS 137 NERVOUS SYSTEM 138 BRAIN 13 ...
128 Human Body A human body is made up of 100 trillion. CELLS of different types. Similar cells are grouped to form tissue, and ...
Human Body^129 Integumentary Hair, skin, and nails protect the body from germs, system injury, heat loss, and drying out. Skelet ...
130 The skeleton is the inner framework of. BONES that supports and gives shape to the human body. It also protects some of the ...
This strong yet flexible material is a living tissue, made up of bone cells embedded in a matrix of fibres. Bone is not solid – ...
132 Human Body Body movement is brought about by muscle, a tissue that can contract. There are three main types: skeletal muscle ...
Human Body^133 HOW DOES SKIN CONTROL BODY TEMPERATURE? When the body is hot, sweat glands secrete a watery fluid onto the skin. ...
134 Human Body WHY DO WE HAVE WHITE BLOOD CELLS? White blood cells destroy germs and damaged tissue. A drop of blood contains ab ...
Human Body^135 Blood is driven around the body by the heart, a powerful muscular pump that never stops beating. The heart is a d ...
136 Human Body The process of taking in oxygen and expelling carbon dioxide is called respiration. When you breathe in, oxygen f ...
The main organs of the respiratory system are the lungs two large organs that expand and contract. Each has a network of airwa ...
138 Human Body The brain, nerves, and spinal cord make up the nervous system. It processes information from the sense organs and ...
«
2
3
4
5
6
7
8
9
10
11
»
Free download pdf